Pharmaceutical Analysis CHEM1108 PDF

Pharmaceutical Analysis CHEM1108-Advanced Instrumental Analysis Dr Tamim Chalati Senior Lecturer in Pharmaceutical Science 22/03/2024 1  Outline Introduction of pharmaceutical analysis and its uses. Analytical method s...

Pharmaceutical Analysis CHEM1108-Advanced Instrumental Analysis Dr Tamim Chalati Senior Lecturer in Pharmaceutical Science 22/03/2024 1  Outline Introduction of pharmaceutical analysis and its uses. Analytical method selection. Examples of pharmaceutical/analytical methods. Applications and analytical methods. Dosage forms quality control tests/analysis examples. Quiz. Workshop. 2  Analytical Methods (AM) Why do we need Analytical Methods? What is the purpose of Analytical Methods in the Pharmaceutical Analysis? 3  Pharmaceutical Analysis (PA) Questions PA methods are used to answer 1. Identity of a substance 2. Chemical structure 2D and 3D 3. Physicochemical properties (mp, density, lipophilicity) 4. Interactions between drug and excipients 5. Quantity of active compound, impurities and excipients 6. Rate at which a drug is released from the formulation 7. Stability of a drug in the formulation – shelf life of the product 4  When and where do we need AM? 1. New Drug Entities (Drug Discovery) 2. Research and Development (R&D) 3. Development and Design of a Dosage Form (Formulation) 4. Stability Studies of a New Formulation 5. In Process Control (IPC) 6. Quality Control (QC) of the final product 5  Analytical Method Selection 1. Information (properties) that should be obtained! 2. Available amount of material to be analysed! 3. Invasive or non-invasive methods! 4. Reliability of method (specificity, selectivity etc.)! 5. Time required to obtain set of data! 6. Cost of experimental work! 6  Golden Rules For Analysis Method Development 1. Keep it simple! 2. Literature search! 3. Use validated and calibrated instruments! 4. Study influence of only one parameter at the time! 5. Validate new method! 7  Titrimetric and Chemical Analysis Titrimetric analysis is a method of analysis in which a solution of the substance being determined is treated with a solution of a suitable reagent of exactly known concentration. The reagent is added to the substance until the amount added is equivalent to the amount of substance to be determined. Applications Used in standard pharmacopoeial methods for the assay of active compounds (unformulated drugs), excipients and some formulated drugs Advantages Higher degree of precision and accuracy than instrumental methods (±0.1%) Methods are robust, cheap and can be automated They are absolute methods and are not dependent on the calibration of an Instrument 8  Titrimetric and Chemical Analysis Limitations They are non-selective, time-consuming and require a greater operator skill than routine instrumental methods Large amounts of sample and reagents are required Based on the reactions involved, the titrimetric analysis can be classified into four main types: Neutralization titrations or acid-base titrations (Aqueous and non-aqueous). Redox titrations. Precipitation titrations. Complexometric titrations. 9  Titrimetric and Chemical Analysis Examples Aqueous titration – assay of perchloric acid, thiamine hydrochloride, benzoic acid, nicotinic acid etc. RCOOH + NaOH → RCOONa + H2O Indirect titration (estimation of esters) – assay of benzyl benzoate, cod liver oil, coconut oil, ethyl oleate etc. RCOOR’ + XS NaOH → RCOONa + R’OH + NaOH (not reacted) NaOH (not reacted) + HCl → NaCl + H2O Non-aqueous titration – assay of: barbiturates, uracils etc. Argentometric titration – assay of sodium chloride, thiamine HCl, carbromal. AgNO3 + RCl → AgCl(s) + R+ + NO3- 10  UV/VIS spectroscopy Applications UV spectrum as one of a number of Pharmacopoeial identity checks Quantification of drug in formulation where there is no interference from excipients Determination of pKa, partition coefficients and solubilities of drugs Determination of drug release from the formulation, kinetics of drug degradation Advantages Easy to use, cheap, robust and routine method for determination of physicochemical properties of drugs Limitations Moderately selective to drugs with distinct chromophore, not applicable to analysis of mixtures, requires calibration of instrument and method 11  UV/VIS spectroscopy Instrumentation UV Spectrum 12  IR spectroscopy Applications Fingerprint check for the Identity of raw materials used in industry Used to characterise samples in the solid or semi-solid states Can be used to detect polymorphs of drug! Advantages Gives unique complex fingerprint for examined compound, selective Limitations Rarely used as a quantitative technique Sample preparation requires a good level of experience especially when KBr disks are used 13  IR spectroscopy Instrumentation IR Spectrum 14  Mass spectrometry (MS) Applications It is a specific method for determining or confirming identity and/or structure of drugs Often is coupled with Gas Chromatography or Liquid Chromatography as such is used for characterising impurities GC-MS and LC-MS are highly sensitive hence are used for traces analyses Advantages No 1 method for getting rapid identification and structure of traces/impurities Limitations It is not yet recognised as a quality control (QC) tool Instrumentation is expensive and requires highly skilled workers 15  Mass spectrometry (MS) Instrumentation MS Spectrum 16  NMR spectroscopy Applications Used for the characterisation of the exact structure of both row materials and end products It can determine impurities (enantiomeric etc.) without separation Has good potential for quantitative analysis of drug in the final product without previous separation Advantages Provides more information about molecular structure than any other technique Limitations Requires more sample than some other techniques, instrumentation is considerably more expensive than for other techniques and requires a specialist operator 17  NMR spectroscopy Instrumentation Spectrum 18  Scanning Electron Microscopy (SEM)/ Transmission Electron Microscopy (TEM) Applications used for the characterisation of surfaces or the size. It is capable of providing information about morphology, surface topology and size Advantages gives great resolution (below 1nm) and unique information about surface topology Limitations Applicable only to stationary systems 19  Scanning Electron Microscopy (SEM)/ Transmission Electron Microscopy (TEM) - For determining particle size and morphology SEM TEM 20  Scanning Electron Microscopy (SEM)/ Transmission Electron Microscopy (TEM) Spider (SEM Image) 21  Atomic Force Microscopy (AFM) Applications Used for the characterisation of the sample surface Can distinguish between different compounds that are forming surface of material. Advantages Gives information about morphology of surface as well as surface composition for mixtures of two or more compounds. Limitations Not applicable to liquid materials and requires a specialist operator 22  Atomic Force Microscopy (AFM) AFM AFM Images 23  Dynamic light scattering (DLS) Particle size in a colloidal system Dynamic Light scattering (DLS), (Malvern), Nanosizer, Zetasizer 24  Zetasizer Zeta Potentiel 25  Rheology Applications Used for the characterisation of semisolid systems It can determine phase transitions Has good potential for stability prediction of gels, ointments, creams and other semisolid dosage systems Advantages Gives information about physical and chemical changes to the applied mechanical stresses Limitations Applicable only to semisolid materials and requires a specialist operator 26  Rheology Rheometer Textural Analyser 27  X-Ray Diffraction (XRD) Applications Used for the characterisation of solids (crystals and powders) Determines crystalline structure, detects phase transitions Has good potential for quantification of amorphous and crystalline phase in the system Advantages Provides unique information about 3D crystal structure Limitations Not applicable to liquids and requires a specialist operator 28  X-Ray Diffraction (XRD) XRD XRD Diffractogram 29  Other useful techniques Raman Spectroscopy: is a non-destructive chemical analysis technique which provides detailed information about chemical structure, phase and polymorphism, crystallinity and molecular interactions. It is based upon the interaction of light with the chemical bonds within a material. Fluorescence Spectroscopy: is an investigative method based on the fluorescence properties of the sample under study and is used for quantitative measurements of chemical products. Fluorescence spectroscopy analyses fluorescence from a molecule based on its fluorescent properties. Thermo Gravimetric Analysis (TGA) Differential Scanning Calorimetry (DSC) Hot Stage Microscopy (HSM) Thermally Stimulated Current Spectroscopy (TSC) Hybrids: coupling two or more techniques into one instrument 30  Analytical Methods 1. Identification 1. Classical Analytical Methods – Titrations 2. Melting Point Apparatus 3. Ultraviolet/Visible Spectroscopy (UV) 4. Infra-Red Spectroscopy (IR) 5. Nuclear Magnetic Resonance (NMR) 31  Analytical Methods 2. Structure elucidation 1. Ultraviolet/Visible Spectroscopy (UV) – Chromophore 2. Infra-Red Spectroscopy (IR) – Functional Groups 3. Mass Spectrometry – Mass and Molecular Fragments 4. Nuclear Magnetic Resonance (NMR) – Structure 5. X-Ray Diffraction – Crystal Structure 32  Analytical Methods 3. Quantification 1. Classical Analytical Methods – Titrations 2. Ultraviolet/Visible Spectroscopy (UV) 3. High Performance Liquid Chromatography (HPLC) 4. Gas Chromatography (GC) 33  Analytical Methods 4. Phase Transitions 1. Thermogravimetric Analysis (TGA) 2. Differential Scanning Calorimetry (DSC) 3. Differential Mechanical Analysis (DMA) 4. X-Ray Diffraction (XRD) 5. Nuclear Magnetic Resonance (NMR) 34  Analytical Methods 5. Surface Images and Surface Properties 1. Scanning Electron Microscopy (SEM) 2. Transmission Electron Microscopy (TEM) 3. Atomic Force Microscopy (AFM) 35  Specific instruments Final dosage forms: tablets, capsules, pellets, anal and vaginal preparations eye, ear and nasal preparations, infusions, syrups etc. 36  Powder properties Bulk density Tapped density Repose angle http://www.copleyscientific.co.uk Sieves 37  Disintegration test Apparatus for disintegration http://www.copleyscientific.co.uk British Pharmacopoeia (BP) 38  Dissolution test http://www.copleyscientific.co.uk Paddle apparatus Basket apparatus 39  Friability test Tablet Friability apparatus http://www.copleyscientific.co.uk British Pharmacopoeia (BP) 40  Hardness test http://www.copleyscientific.co.uk 41  Uniformity of weight (mass) / content Uniformity of Weight/Mass Uniformity of Content British Pharmacopoeia (BP) 42  Uniformity of Weight BP Weigh 20 tablets at random and determine the average weight Not more than two of the individual weights deviate from the average weight by more than the percentage of deviation shown in the table and none deviates by more than twice that percentage of deviation Tablet weight is important to ensure that each tablet contains an equivalent dosage and to give confidence to the patient. 43  Quiz Tablet Weight (mg) 1 588.8 2 592.8 For a certain medication 3 4 582.0 577.4 product from a recently 5 6 584.8 574.1 prepared batch 20 Tablets 7 8 591.0 598.7 were selected at random. 9 581.9 10 587.0 Then, tablets were weighed 11 577.0 12 581.9 individually, and the weight of 13 580.3 14 593.5 each tablet was noted as in 15 576.1 16 586.8 the table: 17 582.2 18 584.8 19 589.5 20 603.2 44  Quiz If you know that, according to the used pharmacopeia, the deviation of individual weight from the average weight should not exceed the limits given in the table below. The tablet Not more than 2 No tablet can average weight tablets can differ from the (mg) differ from the average weight average weight by more than % by more than % Up to 80 10 20 80-250 7.5 15 >250 5 10 1. Calculate the average weight of the given tablets. 2. Determine if this tablet batch passes or fail the uniformity of weight test according to given limits and why? 45  Quiz For a certain medication product from a recently prepared batch 20 Tablets were selected at random. Then, tablets were weighed individually, and the weight of each tablet was noted as in the table below: Tablet Weight (mg) 1 588.8 If you know that, according to the used pharmacopeia, 2 592.8 the deviation of individual weight from the average weight 3 582.0 should not exceed the limits given in the table below. 4 577.4 5 584.8 The tablet average Not more than 2 No tablet can differ 6 574.1 weight (mg) tablets can differ from the average 7 591.0 from the average weight by more than 8 598.7 weight by more than % 9 581.9 % 10 587.0 Up to 80 10 20 11 577.0 80-250 7.5 15 12 581.9 >250 5 10 13 580.3 14 593.5 1. Calculate the average weight of the given tablets. 15 576.1 16 586.8 2. Determine if this tablet batch passes or fail the 17 582.2 18 584.8 uniformity of weight test according to given limits and 19 589.5 why? 20 603.2 46  Quiz: Answer 1. The average weight= the total weight of the 20 tablets/20 =11713.8/20=585.7 mg 2. As long as the average weight is > 250 mg→ Not more than 2 tablets differ from the average weight by more than 5% and none should differ from the average weight by more than 10% 5% deviation= 29.3 mg → accepted limit (556.4 mg to 615.0 mg) and only 2 tablets or less can exceed this limit. For our batch none of the tablets exceeded this limit. 10% deviation = 58.6 mg→ accepted limit (527.1 mg to 644.3 mg) and only one tablet can exceed this limit. For our batch none of the tablets exceeded this limit. All the 20 tablets weight deviations do not exceed the limit of + 5.0% (nor 10%) and therefore, they are considered to pass the test. 47  Workshop Job interview questions 48  Analytical Methods (AM) Task 1 You are working in Analytical Lab which supports Discovery Department of major Pharma Company. You have been presented with 100 mg of white powder and asked to provide as much physico- chemical properties (information) as possible. Which analytical techniques would you use? 49  Analytical Methods (AM) Task 2 You are working as formulation scientists in Pharmaceutical Company. Your team is developing new dosage form. Which analytical methods would you use to test performance and stability of your product? 50  Analytical Methods (AM) Task 3 You are Senior Scientist in Quality Control department of the same Pharma Company. It is time to renew your lab and purchase new analytical instrumentation. Which instruments would you purchase and why? 51